The present invention is generally directed to an improved weighing scale and in particular to an improved weighing mechanism for a weighing scale.
Weighing scales are well-known in the prior art. They find considerable use in commercial weighing operations and in particular in retail food operations. In such use, it is absolutely necessary that strict accuracy and equity be maintained. Consumers are concerned that they receive full weight and value while merchants wish to avoid embarrassing possible prosecution for short weight but yet must be assured of full legitimate profit to survive. Inasmuch as net profit in retail operations today may sometimes not exceed one-half of 1%, weighing scales in such use must be extremely accurate.
Virtually all weighing scales require that the relation between platform displacement and load weight be linear because they include mechanical readout mechanisms having equally spaced graduations or encoders for digital readouts which generate weight indicative pulses, the number of such pulses being proportionnal to platform displacement. Conventional cylinder scales or others having rotary opto-electrical encoding disks or the like typically include traditional rotating balancing and calibrating techniques through the addition of balancing lugs, transverse screws and the like to derive the required linear relation. However, later scales having no such rotary means incident to display or encoding have required the development of other balancing means to secure the required linearity. Unfortunately, the balancing means heretofor developed have in use been difficult to adjust and introduce undesirable friction, hysteresis or even their own non-linear characteristic.
It is therefore an object of the present invention to provide an improved weighing scale.
It is a further object of the present invention to provide a balancing means for a weighing scale which causes the relation between scale platform displacement and load weight to be substantially linear.
It is a still further object of the present invention to provide an adjustable balancing means for a weighing scale to thereby allow the relation between scale platform displacement and load weight to be adjusted for linearity.